PROJECT SUMMARY/ABSTRACT The 11th International Conference on Neural Tube Defects will be held September 16-18, 2019, in Boston, Massachusetts, at the Joseph B. Martin Conference Center at Harvard Medical School. Since its inception in 1999, this biennial event has aimed to break down barriers between differing investigators from different disciplines that study neural tube defects, and to establish effective lines of communication to address important challenges in understanding the mechanisms underlying neural tube defects, implementing effective preventive strategies, and developing interventions to improve the health of affected individuals. As in the past, the 11th International Conference on Neural Tube Defects aims to (1) bring together established and new investigators from a variety of research fields with a shared interest in the causes, consequences, and prevention of neural tube defects; (2) provide a forum for investigators to present their latest research findings; (3) foster the development of new, multidisciplinary and multinational collaborations; and (4) offer trainees opportunities to learn about neural tube defect research and establish relationships with the early career and senior investigators who currently shape the field. The scientific program for the 2019 meeting will focus on four themes that represent key areas of growth in the field and resonate strongly with the neural tube defect research community: (1) modeling and analyses of polygenic inheritance, (2) the ole of epigenetics in gene-environment interactions, (3) innovative strategies for prevention and treatment of neural tube defects, and (4) surveillance and care in low- and middle- income settings. By organizing the conference around these themes, each session will include a mixture of basic scientists, clinicians, and epidemiologists who address a common challenge with different approaches. Trainees will be encouraged to submit their own work for consideration for a poster session and for presentation in a moderated plenary session. A comprehensive evaluation will be conducted, including post- event surveys.